In general, gas electron multiplier technology was developed by F. Sauli, R. D. Oliveira, et al. in the Gas Detector Development Group of the European Organization for Nuclear Research (CERN) for the purpose of detecting high-energy elementary particles in 1997. Although the technology has high potential applicability and accordingly has been variously studied by international advanced research groups, studies on its applications are at an early stage.
In particular, a gas exhibits a relatively higher photoelectric effect and Compton effect with respect to X-rays and γ-rays ranging from several keV to several hundreds keV, and a GEM detector has superior spatial and temporal resolutions. Accordingly, fundamental studies on medical high-quality imaging technology for GEM-based real-time X-ray imaging are actively conducted at present. Advantages of the GEM include low production costs, superior stability, light weight, small thickness, and good flexibility.
Since a GEM detector detects X-rays and γ-rays, or charged particles by ionizing a gas, it features solving disadvantages of a charge coupled device (CCD) that has high operating efficiency only in a visible ray range. In addition, the GEM detector has a wide range of applications since it is effective for measurement of charged particles and can be used as a neutron detector by adding BF3 to a gas in the GEM detector or coating a GEM foil with a neutron stopping material such as boron.
However, studies on applications of the GEM detector are yet at an early stage, and real-time digital imaging technology for visible ray image information on a planar or three-dimensional image by means of multiplication of photoelectrons or Compton electrons due to incident rays using a gas electron multiplier has not yet been developed.